MathOverflow.net: post questions here, with the tag "20-questions" if you want the question asked in person at the next 20 Questions meeting. Advice: get a MO.net user-account! This is a great site for mathematicians (NOT a place for undergrad math help), where you accumulate numerical "reputation" for good questions/answers :)
Evolving guidelines for participation in the seminar.
Once in a while, we mathematicians all come upon a question that screams "this is
easy to someone else, but whom?" On the other hand, we like to hear
questions that are easy for us but hard for others, so we can be
useful. So why not trade, and trade fast?
At the 20 Quuestions seminar, each audience member is offered two minutes to present a question that he or she would like to have answered.
(Those not wishing to present are also valuable participants!)
This should be a question which the presenter believes might be easy to someone else with an appropriate background.
After the presentations, we mingle and share any answers or suggestions we have.
Questions are posted online at MathOverflow.net to be visible to the math community at large.
Can't attend? Email your question to critch@math to have it asked in person at the seminar.
1. Avoid asking questions that require a lot of background, like from your own research.
Stick to questions you think others are at least as prepared for as you are.
When people follow it, this rule results in questions that are fun and
accessible, and you often end up with answers, too. But since usually
the "poser" is the only one really interested in the answer -- at
least at first -- we have adopted the following:
2. Wait until the end of the seminar to discuss solutions, unless of course you can say the answer very quickly :)
This keeps the seminar from degenerating to a dialogue about one
question, which I think is the natural tendency. And just so everyone
feels welcome, we have:
3. You do not have to ask or answer a question! Just hearing what lots of people are thinking in a short time is reason enough to attend.
I think these three ideas, someone recording the questions, and a
critical mass of curious mathematicians are all that's needed for a
successful "Questions Seminar", though time will be the only test.
Questions/answers wiki: questions/answers from inside and outside the seminar are organized here. Check it out!
How it works
Rule #1 at the seminar is:
Old Content
(Thanks very much to Scott Morrison for writing these up, and to many online contributors at the SBS.)